We got a 3 euro bubble gun, and took it apart to see how it worked.
Step 1: Open the Hard Plastic Shell
All of the parts of the Bubble bun were contained inside this shell, it was only held together with 5 screws, so it was not difficult to take apart (well, the screws were quite stiff, and it was hard to do with the wrong sized screw driver, but we did it in the end). We saw a few plastic tubes and a mechanism, so we decided to take out the internal system.
Step 2: Take Out the Internal System.
We now have 2 empty plastic shells, and the mechanism that blows the bubbles. we can see the trigger, some tubes, some cogs, but not really anything else. WE NEED TO GO DEEPER!
Step 3: Take Everything Apart.
Here we see; 2 plastic shells, parts for an enclosed blower fan, 3 amplifying cogs, 2 plastic tubes, a liquid recovery system, a lever to spread a bubble film over a hole, a trigger, and a spring.
Step 4: The Blower System.
The fan used to blow the bubbles was standard, nothing special, however, it is interesting to not that the cogs are all greased to make sure no energy is lost to friction, and the blower fan stabilises itself by balancing on a small nib. You can test this by spinning it like a dreidel, on a flat surface. For each pull of the trigger the fan spins 43 times. This is a battery-less bubble gun, so there has to be a system of blowing the bubbles just by force of the trigger alone. To blow the bubbles, you need a relatively strong amount of wind or air, pushing against the film of bubble liquid. If the fan only rotated one each time you pressed the trigger, there would not be enough force to blow a bubble, to overcome this problem, the engineers included 3 extra cogs in the design, these cogs each had an extra set of teeth on them, a small set, and a large set. They were spun by a large set of cogs on their small set, which spun their large set faster, with these 3 extra cogs, the fan was able to blow a significant amount of air through the bubble film.